Learn Drain Trap Basics from Horizon Services
The Purpose of a Drain Trap
A drain trap is meant to prevent sewer gas from backing up into your home. Any room that has a plumbing connection is susceptible to gas build-up, but the source of that smell can be hard to pinpoint because it’s not something we smell every day. Don’t worry, though—you’ll know it when you smell it.
Drain Trap Functionality
To help drain traps function properly you only need to make sure there’s standing water in the drain; they’re designed to hold some water at all times. The water helps keep sewer gases from escaping the drain. If you have a nasty odor in your home that you can’t explain, it’s a good idea to inspect all the drains in your house.
Drain traps are present anywhere there’s a drain:
- Kitchen and bath sinks
- Washing machines
Most Common Drain Trap Odors
The most common cause of unpleasant odors coming from a drain is a dry trap. Sewer gases can easily escape a dry drain trap and spread throughout a room. This is a smell you do not want in your house! If you suspect a dry drain trap, try running some water down the drain to fill the trap again. The smell should go away fairly quickly once the trap is full.
Locating Drain Traps
Locating drain traps isn’t always easy. Some are obvious, such as in the toilet—that curved section of the commode behind the bowl is the drain and standing water in the bowl helps prevent odors. Other plumbing fixtures have less obvious drain traps that may be hidden in a cabinet or behind a wall. If you look at your kitchen sink, you aren’t likely to see standing water but if you follow the drain line you’ll eventually come to the U or S shaped curve in the pipe where standing water collects. Sink traps not only trap water but also prevent small objects from being flushed away. They’re usually easy to remove, so most items that fall down the sink can be retrieved quickly by simply taking apart a small section of the plumbing.
Showers, tubs, washing machines and other large plumbing fixtures also have drain traps but these are usually hard to find, located under floors or behind walls. Tub and shower traps can be hard to get to; you may have to crawl under your house or cut a hole in the wall behind the fixture. If you suspect a problem with one of these traps, it’s usually best to call a professional plumber to handle the work.
Drains should be used at least every couple of weeks to ensure there’s always water in the trap. Letting a drain trap dry out won’t cause any damage to plumbing or fixtures, but you definitely don’t want those unpleasant sewer smells to creep into your home. Go around the house once a month and run water down each drain for a few minutes, especially in areas of your home that don’t get much use such as guest bathrooms, basement powder rooms, wet bars, utility sinks, etc.